Electric-clock system.



R. D. HIUKOK.

ELECTRIC CLOCK SYSTEM. APPLICATION FILED MAR, 7, 1911.

1,016,499. Patented Feb. 6,1912.

2 SHEETS-SHEET 1..

R. D. HICKOK.

ELECTRIC CLOCK SYSTEM. APPLICATION FILED MAR. 7, 1911.

Patented Feb. 6,1912.

2 SHEETS-SHEET 2.

ROBERT D. HICKOK, F ATLANTA, GEORGIA.

ELECTRIC-CLOCK SYSTEM.

Specification of Letters Patent.

PatenteolFeb. c.1912.

Application filed. March 7, 1911. Serial No. 612,960.

I systems, and has for its object to provide an improved. method of and means for setting the hands of a secondary clock, or synchronizing the same with the master clock, this object being efiected by means controlled by reversing the direction of polarity of the current from the master clock.

In my pending application 563792 filed May 27, 1910, there is disclosed a secondary clock including a magnet and means controlled thereby to set the hands when the polarity of the magnet is reversed the magnet acting also as usual to operate the hands for indicatin time.

The invention herein claimed includes the master clock and associated devices by means ofwhich said secondary clock, or one adapted to operate in the same way, is actuated.

It is usual in electric clock systems to operate the hands of the secondary clock by 3 quill of the hour. hand and properly posimeans of impulses from the master clock, energizing an electromagnet which controls the movements of the hands of the secondary clock, the armature of the electromagnet being moved in one direction for this purpose by means of impulses trans- 'mitted by the master clock, said impulses being of one polarity. In the present sys tem, this method of operation is retained for time marking-purposes, but the master clock also operates to" reverse the polarity of the current at stated periods, for the purpose of setting the hands of the second? ary clock, or permitting them to be set.

The invention is illustrated in the accompanying drawings, in which Figure 1 is a partly diagrammatic view of the' system, including the master and secondary clocks. Fig. 2 is a side view of part of the master clock. Fig. 3 is a partial front elevation of the secondary clock.

Inasmuch as the secondary clock isfully described in the application above referred to, the following brief descrlption of its .movement of this arbor is reduced and construction and method of operation is all that is considered necessary for this application: The secondary clock has a permanent horse shoe magnet 8 between the ,7 branches of which is an electromagnet 9 w which is energized by impulses from the master clock. The armature 10 of this magnet is pivoted upon an axis concentric with the arbor 11 of the minute hand 12, and said armature normally hangs vertically with its lower end between the poles 13 of the permanent magnet, which normally attract said end equally. When an impulse of one polarity is sent through the electromagnet the polarity of the armature is changed and it will swing in one direction and when an impulse of opposite polarity is sent through the electromagnet the polarity of the armature will be reversed and it will swing in the opposite direction. The 75, lower end of the armature carries a pivoted pawl- 14 which engages a minutes ratchet 15 fast on the arbor 11 of the minute hand. By a suitable and well known train the transmitted to the hour hand 17 A spring detent 18 prevents back slip. By this means the time marking movements of the hands are produced, when the lower end of the armature swings to the left. 35

A heart shaped cam 19 is mounted on the tioned to locate the hands at a predetermined point, say 12 oclock, when the gear ing controllin cam is pressed by a roller 20 carried by lever said 'hands is freed. This so 21, which is pivoted at 22, the roller being pressed against the cam by a coiled spring 23 connected to the lever, the spring being of" sufficient strength to turn the cam, and thereby the hands, until the roller runs to the notch in the cam, thereby setting the hands.

After the roller 20 passes the point of the cam in the normal operation of the clock, it 10( is' held out of contact with the cam, until released for the purpose of setting the hands.

It will be understood that if the roller .20 continued to press on the cam after passing the point thereof (that is, after six oclock if the hands are to be set at twelve oclock) it would tend to cause the hands to creep or gain time, since the pressure of the spring 23 would tend to turn the hands forward instead of backward. As the hands and the cam 19 are turned in consequence of the normal operation of the clock the roller will ride up the oath to the point thereof. As the lever 21 swings downin consequence of this action, it wipes against the toe 25 of a ,pivoted catch 26, and when the roller reaches the point of the cam the free end of the'lever 21 passes below the catch, which then swings in until the toe engages the end of the lever,

which is thus held by the catch until the latter is tripped.

The catch has near the lower end thereof a rearwardly projecting pin l'ocated at one side of a spring 31 attached to the detent 18, and said spring depends in position to be struck by the head of the pawl 14: when said pawl is swung to the. right in consequence of the vibration of the armature 10 in that direction. When the polarity of the magnet is reversed as above described it causes the lower end of the armature 10'to swing to the right, carrying with y it the pawl 14 which is forced against the spring 31 and in consequence of the shape of the head of the pawl it is forced, by a cam action against said piece 31, out of engagement with the ratchet wheel 15, and the same movement carries the piece 31 to the right and releases the detent 18 from the ratchet wheel. The spring 23 then acts, and

- by reason of the pressure of the roller 20 against the cam, said cam turns carrying with it the hands, until the'roller runs down to the low point ornotch of the cam, thereby returning the hands to twelve oclock, the setting point. llf the hands have progressed beyond six oclock before the setting action occurs the lever 21 will be caught by the catch 26, but when the setting time arrives the pawl llwill be swung to the right as described, carrying with it the piece 31 which will then strike the pin 30 projecting from the catch and swing said catch to the right releasing the toe 25 from the end of the lever which, then, in consequence of the pressure of the spring 23, will be snapped up against the cam 19 and by pressure thereon will force the hands around clockwise to the setting position. The operation will be more fully apparent from the I pending application above referred to.

.usual quill. The inner end of the pinion E projects backwardly through the front plate of the clock and engages wheel F which is a duplicate of the hour Wheel G. The pinpost M and has a projection ion E is supported in position by the bridges P and Q. Asso far disclosed the description will apply to almost any clock, except the rear projection of-the pinion 1E1 and the driving wheel 15, and the movement may be driven in any suitable manner. Upon the hub of the wheel 15 and revolving with it is 1 once every twelve hours (assumed at twelve oclock). An arm L is ivoted on a which rests upon the two disks and is adapted to drop into the notches of said disks when said notches are registered. The, size of the notches is such that they will allow the arm L to fall about thirty seconds before twelve oclockand will raise it a ain about thirty seconds after twelve ocloc These periods of course may be varied, but are provided in 1 will of course act as the lifter, because of itsmore rapid travel. The arm L is arranged to close a contact at the adjustable screw 40, and this contact reverses the polarity of the magnet 9 by connections to be described.

X indicates, as a whole, a pole changing relay, which is illustrated in diagram, and may be of any suitable type, the coil V of which is connected in series with the master clock contacts represented by the arm L and the contact screw O. The pole changer has four fixed contacts represented at 3, 4i, 5 and 6, and two movable contacts shown at 1 and 2, and normally (that is at all times except 12 oclock) point 1 is in contact with point 5 and point 2 in contact with point 6, this being the normal condition when the secondary clock hands are being advanced minute by minute. The minute circuit closing device of the master clock is indicated at W, connected on one side to the point 1 and on the other side to the battery 'U and point 2. The minute operating devices are not shown, as they are well known in'the art and may be of any ordinary type. The

points 3 and 4 of the pole changer are .con-

nected by wires 3 and 4: to the magnet 9 of the secondary clock. The point 3 is also connected by a cross connections to the point 6, and the point 4 by a cross connection 49 to the point 5, and'when the pole changer is in ordinary position an lmpulse will be transmitted from the battery, at each closure of the contacts W, through said contacts on one side from the battery through the points 1, 3 and wire 3 tothe magnet 9,

and back through wire 4 andcontacts 4 and 2 to the battery.

At the setting time, that is at say thirty seconds before twelve oclock, the connections to the secondary clock will be reversed as follows: The arm L of the master clock by reason of the notches R and Sin the cam disks J and K being registered, will drop and make contact with the screw 0, thus closing the bridged circuit from the battery U through arm L, contact and coil V to the battery. WVhen the coil V is energized it will shift the movable member of the pole changer, carrying the points 1 and 2 to the 4 points 5 and 6, and'from the points 3 and 4,

as indicated in dotted lines in Fig. 1, and in consequence ofthe cross connections 3 and P the impulse transmitted over the line 3 4 will be of reverse polarity, which reverse impulse will actuate the hand setting devices as above described. The contacts of the pole changer will be held in this syn:

chronizing position until say thirty seconds,

after twelve oclock when the arm L will be lifted, the contact broken at O and the relay returned to original position by gravity or by any suitable spring such as represented at- Y. Bythe provision of a pole changer in the circuit between the master and secondary clocks, and by the other means described, the hand setting devices'may thus be operated by reversing the current and said clocks, a magnet in said circuit, means controlled by impulses of one polarity in said magnet to operate the hands of the secondary clock to indicate time, and means controlled by impulses of opposite polarity in said magnet to set the hands of the sec ondary clock.

2. In an electric clock bination of primary and secondary clocks in circuit, a pole changer in said circuit, means automatically actuated by the master clock' to operate the pole changer at definite times system, the comand reverse the polarity of thecurrent in the circuit, a 'magnet in said'circu'it, means controlled by. impulsesof one polarity in said magnet to operate thehands of the secondary clock to indicate time, and means controlled by impulses of opposite polarity" in said magnet to set thehands of the secondary clock.

In-testimony whereof, I aflix my signature in presence of two witnesses.

y ROBERT D. HICKOK.

'Witnesses: i

, JAMES T. Wlucr rr,

" H. V\T..D1z:1-'1'r.' 

